During the past year, almost 700 peptides have been produced by the Branch largely for defining MHC class I restricted T cell epitopes and for defining the nature of the interaction between peptides and class I molecules. A large number of peptides have also been used for preparing anti-peptide sera and for studying class II restricted T cell epitopes. Peptides have been used to prepare antisera to HIV-tax, cytokine receptors, diphenyl oxidase of Cryptococuss neoformans, Section-1, neutrophil cytochrome b558, SH2 domains of regulatory proteins, T cell receptors, Duffy receptor, P. falciparum tubulin, CD16 (FCgammaRIII-2), neutrophil chemotactic receptor, Herpes simplex viral proteins, HLA-DR antigens, mouse XLA protein, Leishmania donovani nuclease, Vaccinia virus proteins and human zap-70 and procine syk tyrosine kinase, RAG-2, and IL-4 cytoplsmic domains; to study the function of ras-related G proteins, integrins, HIV-TAR RNA binding protein, human neutrophil and NADPH oxidase factors p47-phox and p67-phox, malarial circumsporozoite protein, human CD22 cytoplasmic domain, NADPH oxidase src domains, Herpes simplex virus attachment sites, and HIV superantigen effects, and so study CTL recognition of peptides associated with toxoplasmosis, myelin basic protein, which is possibly involved in multiple sclerosis, Friend Virus, Epstein Barr Virus, influenza viruses, and cytomegalovirus.